NAME
DBIx::Class::DeploymentHandler - Extensible DBIx::Class deployment
SYNOPSIS
use aliased 'DBIx::Class::DeploymentHandler' => 'DH';
my $s = My::Schema->connect(...);
my $dh = DH->new({
schema => $s,
databases => 'SQLite',
sql_translator_args => { add_drop_table => 0 },
});
$dh->prepare_install;
$dh->install;
or for upgrades:
use aliased 'DBIx::Class::DeploymentHandler' => 'DH';
my $s = My::Schema->connect(...);
my $dh = DH->new({
schema => $s,
databases => 'SQLite',
sql_translator_args => { add_drop_table => 0 },
});
$dh->prepare_deploy;
$dh->prepare_upgrade({
from_version => 1,
to_version => 2,
});
$dh->upgrade;
DESCRIPTION
"DBIx::Class::DeploymentHandler" is, as its name suggests, a tool for
deploying and upgrading databases with DBIx::Class. It is designed to be
much more flexible than DBIx::Class::Schema::Versioned, hence the use of
Moose and lots of roles.
"DBIx::Class::DeploymentHandler" itself is just a recommended set of
roles that we think will not only work well for everyone, but will also
yield the best overall mileage. Each role it uses has its own nuances
and documentation, so I won't describe all of them here, but here are a
few of the major benefits over how DBIx::Class::Schema::Versioned worked
(and DBIx::Class::DeploymentHandler::Deprecated tries to maintain
compatibility with):
* Downgrades in addition to upgrades.
* Multiple sql files files per upgrade/downgrade/install.
* Perl scripts allowed for upgrade/downgrade/install.
* Just one set of files needed for upgrade, unlike before where one
might need to generate "factorial(scalar @versions)", which is just
silly.
* And much, much more!
That's really just a taste of some of the differences. Check out each
role for all the details.
WHERE IS ALL THE DOC?!
To get up and running fast, your best place to start is
DBIx::Class::DeploymentHandler::Manual::Intro and then
DBIx::Class::DeploymentHandler::Manual::CatalystIntro if your intending
on using this with Catalyst.
For the full story you should realise that
"DBIx::Class::DeploymentHandler" extends
DBIx::Class::DeploymentHandler::Dad, so that's probably the first place
to look when you are trying to figure out how everything works.
Next would be to look at all the pieces that fill in the blanks that
DBIx::Class::DeploymentHandler::Dad expects to be filled. They would be
DBIx::Class::DeploymentHandler::DeployMethod::SQL::Translator,
DBIx::Class::DeploymentHandler::VersionHandler::Monotonic,
DBIx::Class::DeploymentHandler::VersionStorage::Standard, and
DBIx::Class::DeploymentHandler::WithReasonableDefaults.
WHY IS THIS SO WEIRD
"DBIx::Class::DeploymentHandler" has a strange structure. The gist is
that it delegates to three small objects that are proxied to via
interface roles that then create the illusion of one large, monolithic
object. Here is a diagram that might help:
Figure 1
+------------+
| |
+------------+ Deployment +-----------+
| | Handler | |
| | | |
| +-----+------+ |
| | |
| | |
: : :
v v v
/-=-------\ /-=-------\ /-=----------\
| | | | | | (interface roles)
| Handles | | Handles | | Handles |
| Version | | Deploy | | Versioning |
| Storage | | | | |
| | \-+--+--+-/ \-+---+---+--/
\-+--+--+-/ | | | | | |
| | | | | | | | |
| | | | | | | | |
v v v v v v v v v
+----------+ +--------+ +-----------+
| | | | | | (implementations)
| Version | | Deploy | | Version |
| Storage | | Method | | Handler |
| Standard | | SQLT | | Monotonic |
| | | | | |
+----------+ +--------+ +-----------+
The nice thing about this is that we have well defined interfaces for
the objects that comprise the "DeploymentHandler", the smaller objects
can be tested in isolation, and the smaller objects can even be swapped
in easily. But the real win is that you can subclass the
"DeploymentHandler" without knowing about the underlying delegation; you
just treat it like normal Perl and write methods that do what you want.
THIS SUCKS
You started your project and weren't using
"DBIx::Class::DeploymentHandler"? Lucky for you I had you in mind when I
wrote this doc.
First, define the version in your main schema file (maybe using
$VERSION).
Then you'll want to just install the version_storage:
my $s = My::Schema->connect(...);
my $dh = DBIx::Class::DeploymentHandler->new({ schema => $s });
$dh->prepare_version_storage_install;
$dh->install_version_storage;
Then set your database version:
$dh->add_database_version({ version => $s->schema_version });
Now you should be able to use "DBIx::Class::DeploymentHandler" like
normal!
LOGGING
This is a complex tool, and because of that sometimes you'll want to see
what exactly is happening. The best way to do that is to use the built
in logging functionality. It the standard six log levels; "fatal",
"error", "warn", "info", "debug", and "trace". Most of those are pretty
self explanatory. Generally a safe level to see what all is going on is
debug, which will give you everything except for the exact SQL being
run.
To enable the various logging levels all you need to do is set an
environment variables: "DBICDH_FATAL", "DBICDH_ERROR", "DBICDH_WARN",
"DBICDH_INFO", "DBICDH_DEBUG", and "DBICDH_TRACE". Each level can be set
on its own, but the default is the first three on and the last three
off, and the levels cascade, so if you turn on trace the rest will turn
on automatically.
DONATIONS
If you'd like to thank me for the work I've done on this module, don't
give me a donation. I spend a lot of free time creating free software,
but I do it because I love it.
Instead, consider donating to someone who might actually need it.
Obviously you should do research when donating to a charity, so don't
just take my word on this. I like Matthew 25: Ministries:
, but there are a host of other charities that can
do much more good than I will with your money. (Third party charity info
here:
METHODS
prepare_version_storage_install
$dh->prepare_version_storage_install
Creates the needed ".sql" file to install the version storage and not
the rest of the tables
prepare_install
$dh->prepare_install
First prepare all the tables to be installed and the prepare just the
version storage
install_version_storage
$dh->install_version_storage
Install the version storage and not the rest of the tables
AUTHOR
Arthur Axel "fREW" Schmidt
COPYRIGHT AND LICENSE
This software is copyright (c) 2017 by Arthur Axel "fREW" Schmidt.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.